Recording an Orchestra with 3 Microphones?

[Robert R. Schultz]

Hello, I'm shooting a video this weekend during a concert featuring a small, (~25 person) chamber string orchestra in a lecture hall. The only mics I can get my hands on are a friend's matched pair of Rode NT5s, and my own Rode NTG-3.

The video is for the conductor's resume`

Because of some weird logistics, any recording techniques involving microphones placed above and in front of the orchestra cannot be used (but they could be placed just slightly above and behind). Not sure how to describe the acoustic qualities of the room (since I haven't heard the orchestra in there yet) but as far as the shape of the venue–think of an amphitheater (the walls are wood panels).

What recording techniques and microphone placement would you recommend for this (potential) setup? Please give me your input and experience in this. I'm stuck.

[Vincent Rozenberg]

Where do you record on?

[Bob Hart]

Hopefully, the generous people who advised me will soon help you out as well.


In meantime, have a look at this older thread.

http://www.dvinfo.net/forum/all-thin...vironment.html


Here is the outcome which also shows the decca tree we finally settled on :-

http://www.youtube.com/watch?v=TWpBhIyuq8k


The decca tree consisted of a light stand, a threeway metal branch I made up long ago for lighting and three squeegee mops and handles for the telescopic arms and some pipelagging foam for acoustic insulation.

[Robert R. Schultz]

Hi Vince, I use a Mackie 802-VLZ3 mixer and use the rca output to connect to my 2010 Macbook Pro and record with Soundtrack Pro. I know it's not the best setup, but I do visual things, audio is a work in progress for me. Thanks for the quick response!

[Robert R. Schultz]

Originally Posted by Bob Hart

Hopefully, the generous people who advised me will soon help you out as well.

The decca tree consisted of a light stand, a threeway metal branch I made up long ago for lighting and three squeegee mops and handles for the telescopic arms and some pipelagging foam for acoustic insulation.

Thanks Bob! The recording is beautiful to my ears. Thanks for responding. Unfortunately the mics I have are all directional.

BTW: It's a community chamber orchestra that I'm recording, so it's not like a bunch of pros

[Robert Turchick]

you really only need two mics BUT the placement is absolutely critical.
I did orchestral recordings in NY for 12 years and while we generally had a ton of mics setup, they were more for fill IF we needed them. (obviously we multitracked & mixed in post) BUT the bulk of the sound was the stereo pair slightly back and above the conductor's head.
For live performances, we generally just used the pair to keep the stage clean.
If you can't get the mics in front of the orchestra, the sound will be very dull and out of balance.
Can you get the mics on a stand just in front of the conductor's music stand? Even if they were low enough as to not obstruct his view, you'd get a better sound. Use either an XY or Ortif pattern and angle them around 45 deg up. That would be a worst case and very hidden but still provide useable sound.

Oddly, as I was typing this, someone mentioned the Decca Tree. Great setup but a bit finicky. I did work with Decca on one recording and they used a pair of M49's as the mains, those plus the other 40-50 mics were run into a console, tracked to a pair of Sony PCM 48 track machines BUT the main stereo bus from the board was run to Decca's proprietary 2 track digital recorder. And as I mentioned, the bulk of the sound was the M49's and while they were recording, the chief engineer would blend in the other mics to fill in the sound.

[Bob Hart]

Robert.

This was a recording from the rehearsal a week earlier with a single Rode NT2a in centre and two Sony C74 directionals as the side mikes.

YouTube - FRA DIAVOLO EXTRACTS WEB EXPORT.mp4

The Sonys were not arranged correct for decca tree but were pointed about 40 degrees offcentre left and right, not crossed, which put a couple of lobes on each in what I thought would be the right direction for the flute and woodwind.

The sound from the directionals is a bit gritty compared to the two added NT2a mikes I had for the following week.

From upright pole to each mike on each arm was about 900mm on both nights.

As a desperation measure, to omni-directionalise one of the mikes, try pointing it directly at a piece of thick plateglass about a foot square or a ceramic floor tile, something shiny-hard which will not resonate and poison your sound. Experiment with the distance between the flat surface and end of mike for best omnidirectional effect.

You will need to test for best effect in the orchestra with the centre mike pointing at the hard surface either down or up. Up will probably be better. You might need some foam or carpet glued on the opposite face of the glass or tile to dampen resonances. Acoustic isolation from whatever support frame you use is essential. I supported the arms in foam lagging tubes fastened with cable ties and supported the mikes themselves on the arms in foam blocks strapped with cable ties to the squeegee heads.

Mikes on the rehearsal night went three separate channels into a Yamaha mixer, mixed to two channels with centre channel dominent.
One the performance night a Sound Devices three channel field mixer was used the same way. - The recordist chased level on the centre channel whereas I had left all the channels untouched once I had found my preference and only used the master to control the combined level to the recorder.

Once I had it set I did not ride it but kept it low. On the performance night you can hear whips as the recordist pulled the level down for the woodwind when it got a bit strong. He had only done location voice recording on films and had not recorded music previously.

left mike and centre mike to left channel - right and centre mike to right channel.

The two-mike solution suggested by the other Robert might be the best go. He does this for a living and his knowledge should be taken over my suggestions.

[Bruce Watson]

The classic ways to record a group of instruments are shown here:

http://www.schoeps.de/PDFs/stereo-re...chniques-e.pdf

The X/Y, M/S, and ORTF methods are perhaps the most used. Which to use depends on the equipment you have available, hall, ensemble, repertoire, etc. And of course, your personal beliefs and preferences. For example, some people like to try to preserve as much as possible the phase delay information in the sound. Those people typically like X/Y and ORTF styles. Some people like the ability to play with the width of the sound stage in post, and typically like M/S much better because it lends itself to just such manipulation. Note that not all techniques work with all microphone designs. M/S requires figure eight mics for example.

Nothing really wrong with any of these techniques, nor the Decca Tree for that matter. All depends on what you want, what equipment you have, the hall, group, and what they are playing, and a million other things besides.

For all that, placement of the mics is typically critical. In all but a very few halls. For this, you'll have to experiment. Often, a lot. As in hours and hours. In "bad" halls you might find that really weird positions give you the best recordings. Don't try to figure it out or match it to your preconceived notions -- just close your eyes and go with your ears. Trust what you hear.

So get in there and work all the rehearsals you can. Make sure your principle knows that you need the rehearsal time as much as the players do.

Good luck with it.

[Robert R. Schultz]

Yes! Some logistics of the concert changed that could (possibly) allow the NT5s to be placed behind and just above the conductor's head!

Thank you all for your awesome responses. You guys rock!

So the NT5s should be placed as previously mentioned at 45 degrees (though I think it'll have to be a greater angle since the orchestra is positioned in a rather wide orientation in relation to each other with an acoustically opaque material in between? Should they be horizontally level or aimed slightly angled down? Will a small piece of plexiglass work or something foam-based? Where should the NTG-3 (shotgun mic) be placed? And the mix should be with the NT5s fully separate (one on the left channel, the other on right) with the NTG-3 on center?

Thanks again for all the help! I'm very grateful.

[Robert Turchick]

The angle I mentioned was to keep too much direct sound from the front row of musicians entering the mics.

If you have the mics above and back from the conductor, any of the stereo techniques will work...becomes a matter of taste...BUT don't mess with the angle of the mics in relation to each other. You may end up with phasing issues. To adjust the "direction" of the stereo image, you will need to move the mics as a pair. Think of the pair as your ears. If the orchestra is spread out pretty wide, you will need to move the "ears" back further.

If you use three mics (not my fav), you can have the whole rig a bit closer and you are correct that you want hard pan on the left and right and up the middle for the center mic. Adjust the center mic to "tweak" the imaging.

I would angle the "ears" on either setup slightly down...shooting just over the conductor's head.

[Robert R. Schultz]

Originally Posted by Robert Turchick

The angle I mentioned was to keep too much direct sound from the front row of musicians entering the mics.

If you have the mics above and back from the conductor, any of the stereo techniques will work...becomes a matter of taste...BUT don't mess with the angle of the mics in relation to each other. You may end up with phasing issues. To adjust the "direction" of the stereo image, you will need to move the mics as a pair. Think of the pair as your ears. If the orchestra is spread out pretty wide, you will need to move the "ears" back further.

If you use three mics (not my fav), you can have the whole rig a bit closer and you are correct that you want hard pan on the left and right and up the middle for the center mic. Adjust the center mic to "tweak" the imaging.

I would angle the "ears" on either setup slightly down...shooting just over the conductor's head.

Sounds like a great setup that should be relatively simple!

What should the distance be between the two mics?

[Philip Howells]

My own preference is a Decca tree but it's not always suitable for the venue.

As a fall back I've found our now discontinued AT825, suspended on a modified lighting stand above and equidistant from all sections of the band/orchestra the best alternative. It's certainly quick. The distance from the players has to be balanced against the liveliness of the venue, the greater the natural echo, the closed the mic must be.

[Robert Turchick]

Originally Posted by Robert R. Schultz

Sounds like a great setup that should be relatively simple!

What should the distance be between the two mics?

Bruce's document from Schoeps a few replies up (#8) has all the proper distances and angles for mic placement. Happy recording!

[Bob Hart]

Robert.


The Shoeps chart recommended is a good guide. Note the boxed comment about the wide spaced mikes in the bottom right of the chart and reference to localization and "instability".

The decca tree is a variation on wide mike placement.

If you listen to my recordings closely, especially the rehearsal recording, you will observe particular instruments to be apparently moving around across the stereo channels as an example of this "instability".

[Steve House]

Originally Posted by Robert R. Schultz

Yes! Some logistics of the concert changed that could (possibly) allow the NT5s to be placed behind and just above the conductor's head!

Thank you all for your awesome responses. You guys rock!

So the NT5s should be placed as previously mentioned at 45 degrees (though I think it'll have to be a greater angle since the orchestra is positioned in a rather wide orientation in relation to each other with an acoustically opaque material in between? Should they be horizontally level or aimed slightly angled down? Will a small piece of plexiglass work or something foam-based? Where should the NTG-3 (shotgun mic) be placed? And the mix should be with the NT5s fully separate (one on the left channel, the other on right) with the NTG-3 on center?

Thanks again for all the help! I'm very grateful.

My first thought is the NTG-3 should not be used at all UNLESS you need to cover and isolate a soloist or solo vocalist performing with the orchestra. Another use would be to capture speech if the conductor was doing any announcements or discussion. Otherwise, just because you have one in your kit doesn't mean you have to use it for every job and for an orchestral recording I don't think it would add anything to a conventional 2-mic stereo array.

Of much greater importance than deploying the NTG-3 is the restrictions they're imposing on you with regard to mic placement and that's a fight I suggest you take on. If they want the recording done at all, they need to have it done right (especially if it's for the conductor's resume!!!) and that means that technical considerations regarding proper mic placement need to supercede almost anything else. So they don't want the audience to see the mics between them and the orchestra or on-stage? ... Tough s**t! That's where they have to go if we're going to get a decent recording. You can get them there unobtrusively, but invisible is too much to ask. Restricting you to high and BEHIND the orchestra, so the instrument's sound fields are projecting AWAY from the mics and the left/right & fore/back spacial relationships are inverted, is just plain ridiculous and unacceptable. Using your pair of NT-5s in a classic X/Y coincident stereo or ORTF near-coincident arrangement, placed together high on a stand in the centre aisle behind the conductor at about the height of his head or a little higher, initially at about the 3rd or 5th row back from the stage lip and adjusting position from there while listening on cans during a pre-performance sound check would be my starting point. Don't mix the two mics while recording, send the left mic 100% to the left channel and the right mic 100% to the right channel - you can fine tune the mix in post if necessary for balance.